Tunable shape memory effect and superelasticity in Ti-19.5Zr-10Nb-0.5Fe shape memory alloy wires

The Ti-19.5Zr-10Nb-0.5Fe shape memory alloy (SMA) wires were prepared based on industrial-grade alloy ingot weighing 50 kg using the self-consumable arc melting. Studies were conducted to examine the microstructures and shape memory behavior of the alloy wires associated with different cooling treatments after annealing. The air-cooling samples are determinated to β phase, which exhibit a maximum superelastic recovery strain of 3.7% with a critical stress of 400 MPa for stress-induced martensite transformation (SIMT). For the water quenched samples, martensite coexists with β matrix in room temperature. The martensite deformation mainly occurs upon loading and a shape memory recovery strain of 2.4% was finally obtained. Therefore, tunable shape memory effect and superelasticity have been obtained in the Ti-19.5Zr-10Nb-0.5Fe shape memory alloy wires. • Ti-19.5Zr-10Nb-0.5Fe alloy wires were prepared based on industrial-grade alloy ingot. • Superelasticity recovery strain of 3.7% was detected in the air-cooling sample. • Shape memory recovery strain of 2.4% was achieved in the water quenched sample.